Anterolateral Thigh (ALT) Flap

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Preoperative Considerations


  • Donor site morbidity
  • Issues with flap viabilitym carring, and possible need for additional surgeries.
  • Long-Term Outcomes: Discuss possible long-term implications, including changes in sensation, appearance, and strength in the donor site area.


  • Supine
  • OK to paralyze unless nerve stimulation in neck


  • None


  • Scalpel, scissors, and dissecting instruments for tissue dissection and preparation.
  • Microsurgical instruments, including microforceps, microscissors, and microneedle holders, for precise microvascular anastomosis.
  • Bipolar cautery or diathermy for hemostasis.
  • Vessel loops or vessel clamps for temporary occlusion of blood vessels.
  • Microvascular clamps for vessel occlusion during anastomosis.
  • Suture materials, such as 8-0 or 9-0 nylon or polypropylene sutures for microvascular anastomosis and 4-0 or 5-0 absorbable sutures for wound closure.

  • Doppler Probe: Used for identifying and assessing blood flow in vessels during dissection and anastomosis.
  • Tourniquet: A pneumatic tourniquet may be used to achieve bloodless surgical fields during the procedure.
  • Flap Harvesting Instruments: Dermatome for harvesting skin grafts from the forearm. Tissue retractors and elevators for exposing and dissecting tissue layers. Hemostatic agents, such as surgical clips or electrocautery, for controlling bleeding during flap harvesting.
  • Microvascular Anastomosis Equipment: Operating microscope with appropriate lighting. Microsurgical instruments mentioned earlier. Loupes or magnifying glasses for surgeons who do not use a microscope. Microvascular anastomosis couplers (optional), which can facilitate faster anastomosis in some cases.


  • ASIS and lateral patella line
  • Midline should be the middle of the flap
  • Most perforators are within a 3cm diameter
  • Flap is designed based on the reconstructive needs
  • Pinch test is performed to determine passivity of closure

  • this the medial (superior ) flap marking. start here
  • underneath fascia is visible
  • Fascia is then incised




Postoperative Considerations


  • Enourage early ambulation

Follow Up:

  • Outpatient physical therapy

Operative Note

Surgeon(s): ***

Assistant Surgeon(s):  ***

Preoperative Diagnosis: ***

Postoperative Diagnosis: Same

Procedure(s): ***

Anesthesia: General

Implants: None


Drains: None

Fluids: See anesthesia record

EBL: Minimal

Complications: None

Counts:  Correct x2

Indications: ​***

Findings: As expected

Procedure in Detail:

The patient was seen in the preoperative holding area with a H&P was updated, consents were verified, surgical site marked, and all questions and concerns related to the proposed procedure were discussed in detail.  The patient was transferred to the operating room by the anesthesia team.  The patient underwent general anesthesia with endotracheal intubation. Tegaderms were placed over the eyes. The patient was prepped and draped in the standard fashion for maxillofacial procedures.  A time-out was performed and the procedure began.

Once the ablative portion had been completed and margins were confirmed on frozen analysis to be negative, we evaluated the ablative defect.  The defect measuring approximately 12 x 11 cm.  This was then marked out on the lateral thigh after identifying the midpoint between the anterior superior iliac crest and the superior lateral border of the patella.  An ellipse was marked along the septum and a hand-held Doppler was used to identify cutaneous perforators along the midpoint.  The medial aspect of the skin paddle was then incised extending down towards the rectus femoris.  Once the intramuscular septum was identified, we then carried it posteriorly towards the fascia lata.  The Chevrons were identified in order to confirm the rectus femoris.  We then identified the cutaneous perforator that had previously been dopplered out through the fascia.  This was noted to be musculocutaneous.  The rectus femoris was then retracted medially and exposed the descending branch of the lateral circumflex femoral artery.  There was some aberrant anatomy and there were two descending branches that were noted and supply perforators to the skin and muscle.  These perforators were dissected and contained within the flap.  Nerve to the vastus lateralis was also identified.  Once the perforators were completely exposed, the decision to harvest both the vastus lateralis as well as fat and skin was determined.  We then islanded our skin paddle along the posterior aspect posteriorly.  This lateral incision was made and carried through the fascia lata and then working from inferior to superior, the skin paddle was dissected off the underlying remaining portion of the vastus lateralis.  The distal aspect of the pedicle was then clipped and divided and from inferior to superior direction, the skin paddle was elevated.  This was carried up to the profunda.  Skin perfusion was noted through both perforators as well as the main pedicles throughout the entire skin paddle.  There was also noted bleeding from the cut skin edges and muscle.

The flap vessels were then clipped and divided and this was brought up to the head for insetting.  The muscle and fascia lata was then tacked down to the deep periosteum superiorly in order to prevent any drooping or dehiscence.  Superficially, the skin was closed with a 4-0 Prolenes.  Once adequate securement of the ALT free flap was completed, we then proceeded with microvascular anastomosis.

Hemostasis was confirmed.  The sterile microscope was brought in and docked.  The flap vessels were then flushed with heparin saline with noted good flow.  A branch off the facial artery was then dissected and a branch off the internal jugular vein was found.  These were prepared for microvascular anastomosis.  The lateral circumflex artery was then prepared and sutured to the facial artery with 8-0 nylon sutures in a running continuous fashion.  A 4 mm coupler was identified and secured to the vena comitantes.  Release of the vascular clamps noted good inflow and outflow with return of warmth, color and cap refill to the skin paddle.  There was also noted good bleeding from the cut edges.  Once the microvascular anastomosis was complete, we then inset the pedicle to promote a gentle curve to avoid any kinks.  This allowed for optimal positioning of the skin paddle.  Once the skin paddle was complete, the remainder of the muscle was then obturated into the defect.  This was secured deep with 3-0 Vicryl sutures.  We then rotated this inferior subplatysmal skin flap to meet the free flap and secured that with 3-0 Vicryls deep subcutaneously and then 4-0 Prolene superficially.  Two Penrose drains were placed through and through, lying underneath the skin paddle.

At this time, we then performed local advancement flaps in order to close the large donor site defect.  The decision to avoid a split thickness skin graft was decided as we widely undermined posteriorly and anteriorly along the medial aspect of the flap in order to rotate the ellipse and to close it in a near pinwheel fashion.  Then, 2-0 Vicryls deep were used to tack the rectus femoris to the cut end of the vastus lateralis loosely in order to secure the muscle then using a creeping motion with a combination of Kelly clamps and 2-0 Vicryls deep, we advanced along the entire length of the wound.  Superficially, skin staples were used in order to close the cutaneous portion.  This was then wrapped in Kerlix.  There was some tension; however, there was noted to have good perfusion throughout the entire lower extremity.  

The patient's face was then cleaned and the posterior pharynx was suctioned. An OG tube was used to suction out the contents of the stomach. Tegaderms were removed from the eyes. Dressings were placed. The patient was then transferred back to the care of the anesthesia team for extubation and recovery.


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